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Full-Text Articles in Engineering
Byzantine Fault Tolerance For Nondeterministic Applications, Bo Chen
Byzantine Fault Tolerance For Nondeterministic Applications, Bo Chen
ETD Archive
The growing reliance on online services accessible on the Internet demands highly reliable system that would not be interrupted when encountering faults. A number of Byzantine fault tolerance (BFT) algorithms have been developed to mask the most complicated type of faults - Byzantine faults such as software bugs,operator mistakes, and malicious attacks, which are usually the major cause of service interruptions. However, it is often difficult to apply these algorithms to practical applications because such applications often exhibit sophisticated non-deterministic behaviors that the existing BFT algorithms could not cope with. In this thesis, we propose a classification of common types …
On Collision-Tolerant Transmission With Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu
On Collision-Tolerant Transmission With Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu
Hong-Ning Dai
The application of directional antennas in wireless networks brings numerous benefits, such as increased spatial reuse and mitigated interferences. Most MAC protocols with directional antennas are based on the RTS/CTS mechanism which works well in wireless networks using omni-directional antennas. However, RTS/CTS frames cannot mitigate the interfering nodes completely. Besides, they also contribute a lot to the performance overhead. This paper studies the problem from a new perspective. We analyze the transmission success probability under directional transmission and directional reception when the antenna beamwidth is quite narrow. Motivated by the analytical results, we design a lightweight MAC protocol without RTS/CTS …
On The Capacity Of Multi-Channel Wireless Networks Using Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Raymond Chi-Wing Wong, Min-You Wu
On The Capacity Of Multi-Channel Wireless Networks Using Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Raymond Chi-Wing Wong, Min-You Wu
Hong-Ning Dai
The capacity of wireless ad hoc networks is affected by two key factors: the interference among concurrent transmissions and the number of simultaneous transmissions on a single interface. Recent studies found that using multiple channels can separate concurrent transmissions and greatly improve network throughput. However, those studies only consider that wireless nodes are equipped with only omnidirectional antennas, which cause high collisions. On the other hand, some researchers found that directional antennas bring more benefits such as reduced interference and increased spatial reuse compared with omnidirectional antennas. But, they only focused on a single-channel network which only allows finite concurrent …